Linkedin for SalesForce , this is other business development activity done between these two companies that have demonstrated how to leverage new niches of collaboration and partnership.
SalesForce offers its customers the way to improve their sales, Linkedin offers the access to probably the bigger data warehouse of professional people.
Sales people use to have a big bunch of cards with their contacts. One of the issues some companies have is that one a sales person leaves the company the some customers go behind him, and they suddenly find that there is not any information about the people behind the portfolio of customers they have. Yes, this still happens.
So, why to purchase it? You can enable that your commercial people link their contacts to your CRM. So at least you have the name of the people.
For sure, this not ensure commitment, trust and other things, but it is another step to have the ownership of your sales process.